The present invention relates to bridges and, more particularly, to suspension bridges and other cable-supported bridges.
Suspension bridges and other cable-supported bridges have been used for well over a century to span ravines, rivers and other obstructions to travel. Examples of such bridges can be seen in U.S. Pat. No. 11,818 to Yandell et al.; U.S. Pat. No. 418,777 to Akers; U.S. Pat. No. 438,070 to Eddy; and U.S. Pat. No. 478,438 to Kosure. These four patents generally illustrate the five key structural elements of a cable-supported bridge: (1) towers and foundations; (2) anchors; (3) suspension cables; (4) deck-stiffening elements; and (5) decking.
As illustrated in the above patents, these five elements can have various configurations. One consistent aspect of cable-supported bridges, however, is that the deck-stiffening element incorporates a rigid member, such as a beam or stringer, or incorporates a truss. Beams and stringers can be heavy and cumbersome, and consequently can be difficult and/or expensive to install. Similarly, trusses can be complicated and time consuming to assemble.
The present invention is directed toward multiple-use, cable-supported bridges in which the primary lateral and vertical deck-stiffening elements are prestressed cables, or strands, extending along one or both sides of the bridge, and to methods of fabricating such bridges. Several embodiments of the present invention allow workers to erect a bridge without extending large or cumbersome structural members across the span, and without fabricating trusses across the span.
One embodiment of the strand bridge of the present invention is designed to span from a first location to a second location. A first anchor member is fixed near the first location and an opposing second anchor member is fixed near the second location. A number of tensioned cables extend between the first and second anchor members. At least one post is attached to the cables at a point between the first and second anchor members. A cross member is attached to the post and projects from the post in a direction transverse to the lengths of the cables. Decking material extends from the first location to the second location, and can be coupled to the cross member.
Another embodiment of the strand bridge incorporates a pair of first anchor members and a pair of opposing second anchor members. A number of first tensioned cables are tensioned between the first anchor members, and a plurality of second tensioned cables are tensioned between the second anchor members. At least one first post is attached to the first cables at a point between the first and second locations, and a corresponding second post is attached to the second cables. A cross member extends between the first and second posts. Decking extends from the first location to the second location, and can be coupled to the cross member.
The present invention is also directed toward a method of fabricating strand bridges, such as the bridges described in the above embodiments.